中文摘要：

目的探讨氯化两面针碱（NC）对体外培养的肝癌SMMC-7721细胞（以下简称肝癌细胞）DNA聚合酶6催化亚基基因P125蛋白的影响。方法取对数生长期的SMMC-7721肝癌细胞分为给药组和对照组，给药组分别予0．15、0．30、0．60mg／L的NC作用10d。采用集落形成试验观察SMMC-7721细胞的增殖抑制作用；Westernblot法检测P125蛋白表达。结果与对照组相比，给药组NC作用后肝癌细胞集落形成数量明显减少（P〈0．05），并呈现剂量依赖性。给药组P125蛋白表达明显降低，呈剂量依赖性。结论NC可明显抑制肝癌细胞增殖，其作用机制之一可能是从蛋白水平抑制P125表达。

英文摘要：

Objective To investigate the effect of nitidine chloride （NC） on DNA polymerase delta catalytic subunit （ POLD1 ） mRNA and its encoding protein P125 in hepatocarcinoma cell line SMMC-7721. Methods The hepatocarcinoma cell line SMMC-7721 in logarithmic growth phase were divided into treated group and control group, the treated group were given NC of 0.15, 0.30, 0.60 mg/L for 10 ds. Cell proliferation was examined by colony formation assay. The protein expression of P125 were determined by western blot. Results Compared with the control group, the numbere of SMMC-7721 cells and the expression of P125 protein decreased, both in a dose-dependent manner（both P 〈 0.05）. Conclusion NC may inhibit the proliferation of SMMC-7721 cells through down-regulating the expression of P125 protein.